1. Field of the Invention
This invention relates to aircraft hangars and, more particularly, to hangars that are mobile and adjustable for accommodating different aircraft.
2. Description of the Related Art
Additional aircraft hangars and work docks are commonly desired by most aircraft operators and airport authorities. Unfortunately, the construction costs for new hangars and the amount of available space around an airport often prevents their construction. Furthermore, the availability of hangars is a factor that substantially affects the aircraft maintenance operations and aircraft scheduling for an airline company.
Airlines typically have two distinct maintenance operations modes--a line maintenance and a check maintenance mode--that perform both scheduled and non-routine maintenance actions. Because an aircraft is used daily, it needs to be in a continual state of serviceability. Each aircraft in the airline company's fleet is assigned a routing schedule. Once assigned, the smooth operation of the airline company depends on the aircraft being at the gate in a serviceable condition. If it is not, the schedule of the aircraft in the fleet can be affected. Typically, each aircraft operating in the fleet has scheduled maintenance tasks performed during regular overnight visits. The completion of these tasks is of utmost importance to the airline company. The performance of these maintenance tasks at night and during inclement weather conditions often slows down the production of the workers. As a result, the maintenance tasks on the aircraft may not be completed.
Line maintenance operations are driven by the airline company's schedule. Aircraft are assigned to routes dependant on the projected passenger capacity for a given time period or season. For a particular season, a narrow-body aircraft may be required while the next season may require a wide-body aircraft. Also, the number of aircraft at a location may change with different seasons. These two variables require maintenance to be carried out at different facilities at different times of the year. If there are inadequate or insufficient hangar facilities at an airport, the aircraft may need to be re-routed to an airport with adequate facilities so that the maintenance service may be completed.
Factors that make up non-routine maintenance include items that suddenly break or need repair in the normal course of operation. Some of these items can be deferred while some require immediate replacement or repair before the aircraft can be dispatched. Many of these items involve procedures that require many man-hours to complete. They also may require a significant level of disassembly, rework, and re-assembly which, ideally, should be completed at a maintenance base inside a hangar. In many instances, these repairs must be performed outside at airports without hangars.
In some instances, the aircraft may be in service with a particular component that is inoperative. Components operating under these programs, known as a MEL (minimum equipment list) or CDL (configuration deviation list) programs, have time restrictions that specifically limit how long the aircraft can operate in this condition. This puts the aircraft in a state known as "degraded serviceability." If the time limit expires and the condition has not been repaired, the aircraft is considered unserviceable.
The repair or replacement tasks for aircraft operating under MEL or CDL programs are assigned to a line station as the aircraft continues on its normal routing. In the early stages of the time restriction, lessor priority is usually given to those deferrals due to weather conditions or lack of hangar availability. As the deadline nears, the importance of performing these tasks increases. Often at the end of the deferral period, the aircraft is rerouted to a line maintenance base that has a hangar.
One of the factors in deciding to which line station a task will be assigned is whether or not the station has in stock the aircraft part that is inoperative. When the task is deferred due to weather or lack of hangar availability, utilization of the parts inventory is degraded. Many times when the aircraft is later re-routed to a line maintenance base for repair at the end of the deferral period, the local storage facility at the line station maintenance base may not have the particular part in stock. The problem of deferral may have occurred recently on other aircraft, and the part has not yet been restocked. This can lead to the situation where the aircraft is placed out of service, known as AOS. Had the previously assigned line maintenance stations been available with adequate facilities to change the part for which they were allocated, the aircraft would have been returned to the state of full air worthiness sooner.
For all of these reasons, availability or lack of adequate hangar facilities impacts an airline company's initial decision to provide air transportation to an airport. If the airport authorities can offer hangars to airlines, they can attract and maintain airline service. Also, if affordable hangars are available to an airline company, utilization of their fleets can be maximized.
What is needed is an aircraft hangar that is relatively inexpensive to purchase, adjustable for use with different sized aircraft, and moveable to different areas on the airport.